1. Field of the Invention
The subject invention relates generally to metrology of integrated circuit structures and, more specifically, to in-situ metrology of metalized and other thin film formation integrated circuit structures.
2. Background Information
Integrated circuits have become key components of many consumer and commercial electronic products, often replacing discrete components and enhancing product functionality. The semiconductor processing technologies that produce these integrated circuits have advanced to the point where complete systems can now be reduced to a single integrated circuit or application specific integrated circuit (ASIC) device. These integrated circuits or “chips” may incorporate many functions that previously could not be implemented together on a single chip, including but not limited to: microprocessors, digital signal processors, mixed signal and analog functions, large blocks of memory and high speed interfaces. The requisite level of integration, however, significantly complicates the design and manufacturing processes.
In the manufacture or fabrication of integrated circuits, various thin films are formed on a substrate or wafer. An example of thin film formation is metalization. One such metalization process is silicidation. Silicidation is an anneal (sintering) process of a metal thin film resulting in the formation of a metal-Si alloy. Because the correct formation of such thin films is essential to proper structure and/or functioning of the final integrated circuit (i.e. the various components of the final integrated circuit), it is prudent to examine at least some of the metalized substrates. Such examination or analysis is typically accomplished using various metrology techniques. These metrology techniques, however, are destructive to the structure (e.g. integrated circuit) under test and require a separate and additional tool. The additional to further requires more space in the lab. Moreover, these metrology techniques are performed after thin film processing (i.e. after the wafer is removed from the thin film processing system).
Particularly, various optical metrology devices have been developed for measuring and characterizing thin films on semiconductor wafers. One such tool is described in PCT application WO/9902970, published Jan. 21, 1999. This device includes a number of measurement technologies. More specifically, the device includes a beam profile ellipsometer (BPE) (see U.S. Pat. No. 5,181,080); a beam profile reflectometer (BPR) (see U.S. Pat. No. 4,999,014); relatively conventional broad band (BB) and deep ultraviolet (DUV) spectrometers; a broad band spectroscopic ellipsometer (SE) (see U.S. Pat. No. 5,877,859) and an off-axis narrow band ellipsometer (see U.S. Pat. No. 5,798,837). These various optical metrology devices, however, are stand-alone devices that are used on processed substrates remote from the processing device.
What is therefore needed in view of the above, is a system, method and/or apparatus that provides metrology of a thin film or thin film layers in the thin film processing system (in-situ).